1. Field of the Invention
The present invention generally relates to a pulse motor driving apparatus. More particularly, the present invention is directed to such pulse motor driving apparatus which can improve the stability of stepping revolution at the time of low revolution speed and which can also assure a high revolution whenever it is wished.
2. Description of the Prior Art
For the pulse motor used for driving a carriage of printing head in a printer it is generally required that at the time of the printing operation phase a stable and low speed stepping revolution can be obtained on one hand and at the time of the quick drive phase or carriage return a possible higher revolution can be obtained, on the other hand. Hitherto, many attempts have been made to satisfy the requirement. However, all the solutions already proposed have led to a substantial increase in size of the pulse motor itself as well as in its manufacturing cost.